Multilocus Electrophoretic Assessment of the Genetic Structure and Diversity of Yersinia ruckeri

Abstract

Multilocus isoenzyme electrophoresis was used to screen 47 field isolates of Yersinia ruckeri for electrophoretic variation at 15 enzyme loci. Only four electrophoretic types were observed, thus indicating that the genetic structure of Y. ruckeri is clonal. Forty-two isolates were of one electrophoretic type, a reflection of the low amount of genetic diversity extant in this species. Although sorbitol fermentation has been considered to be indicative of a second biotype, no significant gene frequency differences were found between the group of 20 isolates that readily used sorbitol as the sole carbon source and the group of 27 that did not.

Molecular characterization of Portuguese strains of Yersinia ruckeri isolated from fish culture systems

“…On the other hand, although on the basis of results obtained in multilocus isoenzyme analysis (Schill et al 1984) and dot-blot hybridization experiments (De Grandis et al 1988), it has been reported that the genetic intraspeci®c diversity in Y. ruckeri is low, some variability was detected when pulsed-®eld gel electrophoresis was employed (Romalde, Iteman & Carniel 1991). The results obtained in this study in the ribotyping analysis of the Portuguese isolates, with six or seven ribopatterns being detected with any of the endonucleases employed, clearly support this heterogeneity.…”

“…There is a great serological variability within Y. ruckeri, with several intraspecies classi®cations being proposed, comprising four (Romalde, Magarin Äos, Barja & Toranzo 1993) or ®ve (Davies 1990) different O-serotypes. On the other hand, genetic intraspeci®c diversity in this bacterial species is very low as demonstrated by Schill, Phelps & Pyle (1984), using multilocus isoenzyme analysis, by De Grandis, Krell, Flett & Stevenson (1988), employing dot blot hybridization assays on nitrocellulose ®lters, and by Romalde et al (1993), by means of restriction fragment length polymorphism studies.…”

Pulsed-field gel electrophoresis analysis of Aeromonas salmonicida ssp. salmonicida

“…salmonicida according to their geographic origin than multilocus enzyme electrophoresis [13] and ribotyping [10]. These methods were applicable for the species with a low genotypic diver- sity, as in the case of Yersinia ruckeri [14,15]. On the other hand, Ha «nninen and Hirvela «-Koski [16] concluded that ribotyping would provide better results than PFGE for epidemiological studies of A. salmonicida ssp.…”

Molecular heterogeneity inYersinia enterocoliticaand ‘Y. enterocolitica-like’ species – Implications for epidemiology, typing and taxonomy

“…It was suggested that strains biochemically identified as Y. frederiksenii represented more than one Yersinia species [8]. Schill et al [9] used MLEE to assess genetic diversity of Y. ruckeri, which causes enteric red mouth disease, a serious infectious disease in the rainbow trout farming industry that causes economic losses in many countries. Y. ruckeri was fairly clonal as the strains were found to belong primarily to one electrophoretic type.…”